Improvement in calculating-machines



T. ESERSKY.

Calculating-Mah'ines.A

N0. 144,523. vPatssnted Nov. 11,1873.L

l Y 4'/ k (d lfd/wwwa@ xl l UNITED STATES PATENT (DEEIcE.l

THEODOR ESERSKY, OF ST. PETERSBURG, RUSSIA.

IMPROVEMENT IN CALCULATING-MACHINES.

Specification forming part of Letters Patent No. 144,523, dated Novemberll, 1873 application filed August 21, 1873.

To all whom it may concern:

Be it known that I, THEODOR EsERsKY, of St. Petersburg, Russia, vhaveinvented an Improved Calculating-Machine, of which the following is aspecification:

Figure 1 is a face view of my improved calculating-machine, and Fig. 2 atransverse section thereof on the line c c, Fig. 1..

Similar letters of reference indicate corresponding parts in bothfigures.

The object of this invention is to produce a machine or table by meansof which intricate inultiplications and divisions may be rapidly andwithout difficulty ei'ected; and the invention consists in thecombination of an endless band or strip of paper, which contains rows offigures in a peculiar arrangement on both faces, with two rollers uponwhich the said strip is wound, and with a stationary indicater, all ashereinafter more fully described.

In the accompanying drawing, the letters A and B represent two parallelrollers, of wood or other material, hung into a frame, C, of suitablesize. Upon these rollers are wound the ends of a strip, D, of paper orother fabric, which strip has rows of figures printed or written, orotherwise formed, on both of its faces, and which is wound upon the saidrollers in opposite directions, respectively, as shown in Fig. 2, sothat by observing the two rollers from one side the opposite faces ofthek strip will be displayed to the eye. E is a bar or plate, securedwith its ends in the frame C, and placed in such position that it willpractically cover the strip D where the same is between the two rollersA and B-that is to say, the plate E will conceal the portion of Dbetween A and B. Upon the face ofthe plate E are printed or written in arow the units from 1 to 9, either once or twice, as shown, or moretimes. The rows of figures on the strip D are so placed, with respect toeach other and to the units printed upon the plate E, that those rows onD which are in line with the unit 1 on E will be the multiplicands forthe other gures in the saine rows of D, respectively, the remainingfigures on E being the multipliers of such multiplicandson D, to givethe products on the rows respectively opposite to them. Thus, when, asin Fig. 1 on the leftliand side above the strip E, the figure 674C isdirectly above the edge E such iigure will be the multiplicand of theremaining iigures of the same horizontal row of the strip D, theproducts thereof, with the multipliers on E, being respectively apparentdirectly above such multipliers. Thus there will be above the figure 2of E the figures 1348 on D, meaning that twice 674: equals 1348. Abovethe figure 3 the figures 2,022, meaning that three times 674 is equal to2,022, and so on through the several ligures in the row, and in the samemanner through the other figures in other rows. The rows beneath theplate E are arranged the saine way, but one pointed or formed on theopposite face of the sheet D, so that thus both sides of the sheet areutilized, and can be brought to view on the same side of the instrument.

It is easy to observe how this instrument can be used, and how readily,for the multiplication of larger figures, the table thus formed can bebrought to practical use by merely turning the two shafts A B by meansof handles formed at their ends, and thereby bring the requisite row ofiigures of the sheet D directly above or below the 'row of figures onthe plate E.

For division, the apparatus is equally effective, and also for thefinding of logarithms; but I believe it is unnecessary to speciallypoint out the manner in which it is used for each purpose, or to citeexamples of calculation.

The apparatus described may be formed on the same frame C with a seriesof rods, F F, upon which sliding'buttons G G may be hung to facilitatethe process of addition or subtraction that follows the multiplicationor division.

I claim as myinvention and desire to secure by Letters Patent- Thecombination of the two rollers A B for displaying opposite surfaces ofthe strip D, having rows of iigures on both sides, and with theindex-plate or bar E, substantially as herein shown and described.

This speeiiication signed by me this 16th day of November, 1872.

THEODOR ESERSKY.

litnesses: v

CARL HEINRICH KNoor, EDWARD JUsTUs Tnonn.

